کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5178279 | 1502492 | 2017 | 11 صفحه PDF | دانلود رایگان |
- Polypropylene-graft- aminomethylpyridine is added in TPO/MWCNT blends.
- The compatibilizer affects partitioning of MWCNTs in the blend phases.
- TPO blends with a percolation threshold of 0.5Â wt% MWCNTs are prepared.
- Electrical conductivities of the order of 10â2Â S/m are achieved.
- The blend conductivity is optimized by controlling the compounding time.
Composites containing multi-walled carbon nanotubes (MWCNTs) within polypropylene (PP)/poly (ethylene-co-octene) (EOC) blends are prepared using different melt compounding strategies, in the presence of polypropylene-graft-maleic anhydride (PP-g-MA) and polypropylene-graft- aminomethylpyridine (PP-g-Py) compatibilizers. Experimental evidence that MWCNTs are thermodynamically driven to localize preferentially in the EOC phase agrees with estimates of the partition coefficient using measured surface energy values. Addition of PP-g-Py alters the interfacial tension between the PP matrix and the MWCNTs; as a result some nanotubes remain in the PP phase. All blend compositions display lower electrical percolation thresholds compared to the neat matrix, with a minimum at 0.5Â wt% MWCNTs for blends having a co-continuous blend morphology. A kinetic approach, involving pre-mixing the MWCNTs with PP and adding the EOC phase, is employed to monitor the evolution of morphology, MWCNT migration and the ensuing electrical conductivity, as a function of residence time. The morphology is fully developed and MWCNT migration is complete within 2Â min of melt mixing with the EOC. The electrical conductivity is reduced considerably after 2Â min of compounding, due to the migration of the MWCNTs within the dispersed EOC phase.
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Journal: Polymer - Volume 114, 7 April 2017, Pages 231-241